Wind turbine blade and related method of manufacture

Abstract

A blade for a rotor of a wind turbine, said blade comprising a blade body element provided with a carrier surface to accommodate a heating element, an electrically conductive, elongated and substantially planar heating element disposed upon the carrier surface to extend longitudinally substantially along at least the leading edge of the blade preferably at least about 50% of the length of the blade, more preferably at least about 60% and most preferably at least about 70% respectively, an electrical power supplying conductor element located at one end of the heating element, the conductor element substantially extending over the width of the heating element on both sides thereof and electrically coupling thereto, and a joint structure comprising at least one electrically conductive joint element and substantially covering, on both sides of the heating element, the portions of the electrical conductor element that extend over the width of the heating element, wherein said blade preferably contains an instance of said electrical conductor element and joint structure substantially at both ends of the heating element. A corresponding method of manufacture is presented.

The invention claimed is: 
     
       1. A wind turbine rotor blade comprising:
 a wind turbine rotor blade body element constructed from a glass fiber material, the blade body element comprising a carrier surface; 
 a heating element accommodated by the carrier surface, the heating element being an electrically conductive, elongated and substantially planar heating element, the heating element disposed upon the carrier surface and having a first planar surface and an opposing planar surface extending longitudinally substantially along the length of at least a leading edge of the wind turbine rotor blade and having a width extending from said leading edge towards a trailing edge of the wind turbine rotor blade transversely to said length, said heating element extending between two ends thereof defined along said length, said two ends consisting of a first end mutually closer to a tip of the wind turbine rotor blade and a second end mutually closer to a root of the wind turbine rotor blade; 
 an electrical power supplying conductor element including at least one conductor wire located on each of said two ends of the heating element, the electrical power supplying conductor element conveying electric current into the heating element and away from the heating element such that the electric current propagates within the heating element between said first and second ends, the at least one conductor wire of the electrical power supplying conductor element having at least a first portion and a second portion, the first portion contacting the heating element so as to cover a portion of said first planar surface extending along the entirety of the width of said first planar surface, and the second portion contacting the heating element so as to cover a portion of said opposing planar surface extending along the entirety of the width of said opposing planar surface, the width of said first planar surface and the width of said opposing planar surface of the heating element extending transversely to said length of the leading edge of the wind turbine rotor blade, and the electrical power supplying conductor element electrically coupling to the heating element via said first planar surface and said opposing planar surface; and 
 a joint structure comprising at least one electrically conductive joint element that contacts and substantially covers, on both said first planar surface and said opposing planar surface of the heating element, the portions of the at least one conductor wire of the electrical power supplying conductor element that cover the width of the heating element. 
 
     
     
       2. The wind turbine rotor blade of  claim 1 , further comprising: at least one protective aerodynamically optimized layer disposed on the heating element and the joint structure, said at least one layer comprising glass fiber. 
     
     
       3. The wind turbine rotor blade of  claim 1 , wherein the heating element is located closer to the tip than the root of the wind turbine rotor blade. 
     
     
       4. The wind turbine rotor blade of  claim 1 , wherein the heating element has a tapered end, being the end located closer to the tip of the wind turbine rotor blade. 
     
     
       5. The wind turbine rotor blade of  claim 1 , wherein the heating element comprises multi-axial carbon fabric. 
     
     
       6. The wind turbine rotor blade of  claim 1 , wherein the heating element comprises carbon fiber or graphite fiber. 
     
     
       7. The wind turbine rotor blade of  claim 1 , wherein the heating element comprises a plurality of stacked layers. 
     
     
       8. The wind turbine rotor blade of  claim 1 , wherein the electrical power supplying conductor element is configured to bend so as to cover both said first planar surface and said opposing planar surface of the heating element. 
     
     
       9. The wind turbine rotor blade of  claim 1 , wherein the electrical power supplying conductor element comprises a node dividing the electrical power supplying conductor element into at least two branches directed to different sides of the heating element. 
     
     
       10. The wind turbine rotor blade of  claim 1 , wherein the electrical power supplying conductor element comprises at least two separate sub-elements directed to different sides of the heating element. 
     
     
       11. The wind turbine rotor blade of  claim 1 , wherein the electrical power supplying conductor element is configured to bend so as to repeatedly extend over a predetermined side of the heating element. 
     
     
       12. The wind turbine rotor blade of  claim 1 , wherein the heating element comprises two layers between which at least one portion of the electrical power supplying conductor element extends. 
     
     
       13. The wind turbine rotor blade of  claim 1 , wherein the joint structure includes a joint element bent so as to cover both said first planar surface and said opposing planar surface of the heating element. 
     
     
       14. The wind turbine rotor blade of  claim 1 , wherein the joint structure defines at least two layers, one on each of said first planar surface and said opposing planar surface of the heating element, and wherein portions of the electrical power supplying conductor element residing between them. 
     
     
       15. The wind turbine rotor blade of  claim 1 , wherein the joint structure includes a plurality of joint elements defining at least four layers, with two layers on each of said first planar surface and said opposing planar surface of the heating element such that a portion of the electrical power supplying conductor element extends between them. 
     
     
       16. A method for constructing a wind turbine rotor blade, the method comprising:
 obtaining a wind turbine rotor blade body element constructed from a glass fiber material and comprising a carrier surface; 
 disposing a heating element on the carrier surface, the heating element being an electrically conductive heating element having a first planar surface and an opposing planar surface extending longitudinally substantially along the length of at least a leading edge of the wind turbine rotor blade and having a width extending from said leading edge towards a trailing edge of the wind turbine rotor blade transversely to said length, said heating element extending between two ends thereof defined along said length, wherein said two ends consist of a first end mutually closer to a tip of the wind turbine rotor blade and a second end mutually closer to a root of the wind turbine rotor blade; 
 positioning an electrical power supplying conductor element that includes at least one conductor wire on each of said two ends of the heating element so as to contact the heating element such that a first portion of the at least one conductor wire of the electrical power supplying conductor element covers a portion of said first planar surface extending along the entirety of the width of said first planar surface, and such that a second portion of the at least one conductor wire of the electrical power supplying conductor element covers a portion of said opposing planar surface extending along the entirety of the width of said opposing planar surface, the widths of said first planar surface and said opposing planar surface of the heating element extending transversely to said length of the leading edge of the wind turbine rotor blade, so as to electrically couple the electrical power supplying conductor element to said first planar surface and said opposing planar surface such that electric current is conveyed by the electrical power supplying conductor element into the heating element and away from the heating element to propagate the electric current within the heating element between said first and second ends; and 
 deploying an electrically conducting joint structure comprising at least one electrically conductive joint element to contact and substantially cover, on said first planar surface and said opposing planar surface of the heating element, the portions of the at least one conductor wire of the electrical power supplying conductor element that cover the width of the heating element.